This is a nation of duck hooks and banana slices, of half-wedges and long-iron fades, and goose-neck putters. It is a nation in which otherwise sane people think nothing of killing a weekend wearing tangerine pants and aerated shoes, bouncing along in little cars, and whacking away at a dimpled ball.

Golf is back. Not that it ever left, really, but the sport is enjoying its biggest renaissance since Ike built a putting green on the White House lawn in the 1950s. More than 23 million Americans hit the links last year, estimates (the National Golf Foundation (NGF). And the boom in golf has set off a corresponding boom in golf videotapes.

The idea of using video to teach golf isn’t a new one; Bob Mann’s Automatic Golf, the genre’s perennial top seller, first hit store shelves in 1982. But these days it seems every golfer from Jack Nicklaus to Tim Conway’s ”Dorf” has a video reminding you to keep the elbow straight and the head down. More than 100 such tapes, including a new bimonthly golf magazine on cassette, are now available through video stores, golf shops, and mail order. ”Golf tapes have consistently taken the three or four top-selling spots within the sports instructional category,” says Roger Leonard, president and CEO of the marketing firm Video Support Services.

Golf videos run the gamut from Driving for Distance to Precision Putting. Some practice psychology (”Relaaaaaxxxx”). Some boast computerized graphics that put George Lucas to shame. Some even bring in special guest stars (How can you fully appreciate Sean Connery’s body of work until you’ve seen him hit a chip shot?)

What all these tapes have in common is the attraction of measurable improvement: the promise to take 10 shots off your game, add 50 yards to your drive, or give you the sweetest stroke this side of the Babe Ruth of golf, Bobby Jones.

The golf-tape boom is just getting started, says Leonard, who believes the tapes will become increasingly available through catalogs and other channels. And there should be plenty of buyers. According to the NGF, at least 2 million new golfers are expected to hit the links this year. Although golf is already a $20 billion-a-year industry, the group expects it to double over the next 10 years and estimates that as many as 4,000 new golf courses may be needed by the end of the decade just to keep up with demand. That’s more than one new course a day.

It is no secret why. The baby boomers who once deemed golf too, well, boring, are hitting their 40s. After one too many twisted knees from tennis or strained shoulders from softball, golf now seems a more sensible way to enter middle age.

”It’s a sport I can play for the rest of my life,” says Robert Stone, 38, of Dallas, who took up golf while vacationing on Cape Cod last year. ”And it’s the only sport I know that I can actually get better at as I get older.” In the effort to boost his skills, Stone has tried several videocassettes. Though the tapes have helped, he notes that advice he is able to follow while watching in his den ”seems to fade from memory as soon as I get out on the course.”

Compared to the cost of equipment, clothes, and course fees, the price of a few videocassettes means little to most golfers. ”Golfers’ demographics are unbelievable,” says Mike Corcoran, managing editor of The Wide World of Golf, a just-launched bimonthly video magazine that’s partly devoted to instruction. The magazine has already signed on more than 12,000 subscribers, despite the $99.95 per year subscription cost. In fact, one reason golfers are so attuned to video may be that they are the kind of upper-income consumers who were likely to have purchased VCRs long before video caught on with the general population.

But the enthusiasm for video golf has to do with more than buying power. Golfers are ”fanatics,” Corcoran says, ”who want to get their hands on anything and everything that has to do with golf.” And if a tape gives a player even a tiny edge, most golfers would consider it a bargain. ”A golfer will buy anything he thinks will improve his game a few strokes,” says Victor Conte, who runs the pro shop at Philadelphia’s Cobbs Creek Golf Course. ”They really think they can learn by watching.”

Well, can they? Or are the vendors of video just exploiting the desperation of duffers who believe they’re just one small step away from mastering the game?

”If you choose one tape and watch it three or four times, you’ll probably improve your game,” says Ohio State University coach Jim Brown, president of the Golf Coaches Association of America. ”But the problem is that each tape will tell you something else. So pick out one and stick with it.” And one more thing, Brown notes: ”Be sure to practice.”

Watching a tape does offer a golfer something he can’t otherwise get: a chance to see many of the greats demonstrate — and explain — their swings. ”The swing itself is truly mysterious,” says David Gould, executive editor of the (print) magazine Golf Illustrated. Gould attributes the success of golf videos to the insatiable desire golfers have to reach that Zen state, the perfect swing. And, because the swing is a process, ”a thing that moves,” Corcoran says, ”it can’t be communicated in print.”

Partly because average players want to learn from better ones, almost every golfer of note has appeared before the video camera. There are tapes from players in their prime (Nick Faldo, Greg Norman), players past their prime (Billy Casper, Lee Trevino), and players who never really had a discernible prime (Art Sellinger, Dow Finsterwald). Jack Nicklaus’ Golf My Way has sold 150,000 copies over the past five years, despite a stiff $85 price tag. This month, Worldvision will release Golf My Way II, Playing the Game at the same price. And because the game doesn’t change much, older tapes remain valuable and are continually reissued. For instance, three volumes of Lee Trevino’s Priceless Golf Tips have just returned to stores.

Even with the presence of pros such as Nicklaus and Trevino, the Jane Fonda of this market is Bob Mann, a top amateur golfer of the ’50s who admits he rarely plays the game these days. The 54-year-old Mann’s Automatic Golf and its follow-ups have sold more than 1 million copies, despite having a living- room production quality that might seem primitive on America’s Funniest Home Videos.

Why Bob Mann?

”Jack Nicklaus is the finest competitive golfer in the game,” says Mann, ”but how many lessons has he given? I’ve taught thousands of people across the country.” Mann’s video preaches that if a golfer sets up correctly, the swing becomes ”an expansive, pleasurable action that is truly automatic. It’s a process of letting the mind learn to move the club with the lower body.” This theory, Mann says, is responsible for the tape’s remarkable success.

That may be so, but it would seem that Mann’s marketing acumen also has a lot to do with it. He has consistently reduced the price of the tape (VidAmerica has just released Bob Mann’s Complete Automatic Golf Method, a video that combines three earlier efforts, for $19.98) and he was also one of the first to distribute tapes directly to golf pro shops and sporting goods stores. He also got in on the ground floor, just as VCRs were catching on. ”He had the right tape at the right time,” says Golf Illustrated’s Gould.

Besides, who could resist something that promises to ”add 30-80 yards to your drive in 21 days”? At that rate, you could well be smacking the ball 600 yards by summer.